What does microphonic tube sound like?


I have this strange problem since I replaced my old SS preamp to a tubed preamp. Some of my CDs when played through Linn Unidisk sound scratchy. There is this annoying scratchy echoy sound throughout the CD and I can't listen to them. But the same CD, played through my PS1, sounds fine. I had both Linn and PS1 with the old SS preamp, and I didn't have this problem with that particular CD in either player.

I think the problem is with either the CD (bad press?) or the new tubed preamp. The current hypothesis is that the more extended sound from Linn is triggering preamp to misbehave and produce the scratchy sound, because the sound from PS1 is softer in extreme frequency ends. I don't know if what I'm hearing is microphonics, but if it is shouldn't it happen to all the recordings?
jylee

Showing 1 response by jea48

This guy does a good job of explaining it.

My experience with a bad microphonic 6922 tube was as he described with a little ringing sound thrown into the mix.

Tap on top of your preamp lightly with two extended fingers. If you can hear your tapping through a speaker/s you have an excessive microphonic tube/s.